Drill bit



May 27, 1930 R. o. PlcKlN l 1,760,317

Filed March 3. 1927 Patented May 27, 1930 UNITED' STATES' PATENT OFFICEDRILL BIT Application filed March 3, 1927. Serial No. 172,309.'

My invention relates to improvements in drill bits of the roller typeused for the purpose of drilling wells, such as oil, gas and water wellsby the rotary method of drilling.

i The principal object of the invention 1s to rovide a drill bit havingcutters of the rolllng conical type, with a more ehcient device forlocking the cone upon the bearing.

Another object of the invention is to provide a drill bit having cuttersof the rolling conical type with a locking roller positioned and shapedso as to present a square locking shoulder which prevents the conecutter from being forced out vof ostion upon its bearing. Another objecto the'inventin is to `provide a drill bit of the conical type with aroller locking device that is'inserted from within the bearing.

Other objects and advantages of the invention will be apparent from thefollowing description when considered in connection with theaccompanying drawing illustrating a preferred embodiment thereof.

'0n the drawing:

Fi 1 is a sectional front elevation of the drill it, showing a pair ofconical cutters locked upon the bearings.

Fig. 2 is a sectional view taken upon the.-

line 2-2, Fig. 1, showing the position of the locking rollers betweenthe cone cutter and the bearing.

Similar numerals refer to similar parts throughout the several views.

The numeral 10, Figs. 1 and 2 indicates the conical shaped cutter whichis slidingly mounted upon the bearing 12.

The bearing 12 is threadedly mounted upon the shaft 14 and shoulderedagainst the stationarywasher 16, Fig. 1. In this manner the bearing issecurely fastened to the head lloc g rollers 20, Figs. 1 and 2 arepositioned between the conical shaped cutter 10 and the bearing 12.These rollers constitute the locking means, as the are placed so as tohave approximately onealf their bearing in the cutter 10 and one-half inthe bearing 12, the axis of the roller being at right angles to the axisof the shaft, instead of parallel as is the usual practise.

The rollers 20 having their axes at right angles t'o the axis of theshaft 14, the diameter of the roller is approximately double the width,the outer face 22 of the roller is rounded or conical for the purpose ofsupporting the roller against the outer wall o1 the raceway 24.

In assembling, the cutter 10 is placed upon the bearing 12, and therollers 20 are inserted into the racewa 24 throu h the aperture 26 00which is closed y the bloc .28, Figs. 1 and 2. This block is locked andsecured in place by the set screw 30, Fig. 1. The head 18 being splitand separated at 32,*Fig. 1, the washer 16'is placed around the shaft14, and the bear- 65 ing 12 is screwed upon the shaft. Each half of thedrill bit is assembled separately, they are then fastened together readyfor operat- In operation, as the teeth 34 of the cutter 70 10 roll uponthe surface to be cut, the cutter A has a tendency to lift at the heeland force the cones down and to ether at the top, thus closing the space36, ig. 1. This is caused by the greater amount of cutting to be doneupon the periphery of the hole than at the center.

Should a spherical ball be used as a locking means, there isa greatstrain setup which easily forces the two halves of a rounded racewa out.of alignment, and after slight wear tie Ycones get loose upon thebearing. This defect is eliminated by providing a square shoulder andacylindrical roller of the kind described and illustrated. And in 35caseswhere the locking means has to support' an extremely heavy sidethrust owing to the wear of the main bearing, the fiat sided roller willwithstand a greater pressure than a spherical ball, as the latterbecomes crushed 9 in the raceway when tons of drill pipe are bearingupon the drill bit.

I claim:

1. A drill bit, provided with an approximately frusto conical shapedrotatable cutter` locked upon a bearing by means of rollers inserted ina raceway, said rollers being inserted in said raceway through a hole insaid bearing. v

2. A drill bit, provided with an approxi- 1 matel frusto conical shapedrotatable cutter locke upon a bearing by means of c lndrical rollersinserted in a raceway, sai rollers being inserted in said racewaythrough an aperture insaid bearing, said aperture being closed by ablock after said rollers have been inserted.

3. In a drill bit, a rotatable cutter mounted l upon an internallythreaded bearing and locked thereon by anti-friction lockin meanslocated in an annular groove forme .partly in the cutter and partly inthe bearing, said anti-friction locking means being inserted into saidgroove through a hole in said beary annular ing and retained therein bya plug inserted in said hole. v

. 4. In a drill bit, an approximately frusto conical shaped cutterrotatably mounted upon and surrounding the end of an internally threadedbearing and locked thereon by antifriction locking bearings insertedinto an groove formed partly in said cutter and part locking bearingsbeing inserted into said groove through a hole Kconnecting the interiorof the threaded bearing and the groove, and

letlained therein by a block inserted into said 5. In a drill bit, anapproximately frusto conical shaped cutter rotatably mounted upon andsurrounding the end of an internally threaded bearin and locked thereonby antifriction locking earings inserted into annu- .lar grooves, onegroove being formed in the interior of the cutter and the other groovebeing formed on the exterior of the said bearing, the said grooves beingin alignment, said anti-friction locking bearings being inserted intosaid grooves through a hole in said bearin which connects the interiorof the threaded caring with the groove on the exterior of the saidbearing, the said anti-friction bearings being retained in said groovesby a block insertedl 1nto said hole, and said block being retained inposition by a pin passing through the base of the bearin into the saidblock. ROWAN D O. PICKIN.

y in said bearing, said anti-friction

